Introduction

The traditional idea of an adequate diet, in the mere sense of providing enough nutrients to ensure the survival of an individual, to satisfy metabolic needs and to pleasantly gratify the sensation of hunger, has become insufficient to cover the present situation (Bellisle et al, 1998). Nowadays, including this and everything related to food safety, the emphasis is on food potential to promote health, improve well-being and reduce the risk of illnesses (Bellisle, 2002; Palou et al., 2002). Thus, the concept of 'adequate nutrition' is tending to be replaced by 'optimal nutrition'. The notion of 'Functional Foods', 'Foods for Specified Health Use', 'Health Promoting Foods' or 'Foods for particular nutritional uses' appears to indicate that some foods may have a beneficial action on body functions that goes beyond their basic nutritional effects (Contor, 2001; Eckhardt, 2001; Arai et al, 2002).

Functional foods have no universally accepted definition. They are foods in which one of their components, whether it is a nutrient or not, or the particular combination of ingredients, affects target functions of the organism in a specific, positive way, producing a physiological effect beyond its traditional nutritional value. The positive effect of a functional ingredient, or the elimination of an adverse one, may be both its contribution to maintain and promote a healthy state and/or to reduce the risk of suffering a certain illness or disorders (Diplock et al, 1999; Roberfroid, 2000).

The concept of functional foods includes foods that are usual components of the diet and exert their beneficial effects in quantities that are normally consumed in a balanced diet, and excludes pills, capsules and tablets as such (Hasler, 2002). A functional foodstuff should continue being food and its effects should be produced in the usual quantities present in the diet. Therefore, the development of safe and effective functional foods is an excellent opportunity to contribute to the improvement of the quality of life by selecting foods that can positively affect consumer health and well-being (Milner, 1999; Palou et al., 2002).

The effectiveness of these foodstuffs must be conveniently established by sufficient scientific evidence including intervention studies in human populations (Hasler, 2002). A foodstuff may be functional for practically the whole population or only for most of the people within a particular subgroup, for example, those with cardiovascular risk factors, a gastrointestinal disorder, overweight or obesity. Functionality may also depend on one or more individual particularities (Milner, 1999; Eckhardt, 2001). However, consumption of functional foods must not compromise healthy feeding habits and, no matter what, one necessary condition is that safety be guaranteed for the whole population.

Genome and postgenome functional knowledge will be increasingly decisive (Daniel, 2002) as it will enable us to make a headway in understanding the function of genes, biomolecules and cells and their repercussion in the whole organism. The application of modern knowledge and scientific and biotechnological development derived from Molecular Biology are also key issues to improve agronomic performance and to produce foods that are more respectful to the environment and more functional. Furthermore, it is also a determinant for the agroalimentary industry to reach high technology standards and added values (Hasler, 2002).

European framework for food safety assessment

In 1997, one of the reforms of the European system was put into practice. The controversy arose, above all, as a result of the epidemic crisis of bovine spongiform encephalopathy (BSE), and the apparition of the new variety of the Creutzfeldt–Jakob disease in humans. A perception of excessive influence of industrial interests in the committees was detected among consumers and other social sectors. The European Parliament widely expressed its preoccupation with the scientific assessment of the EU in terms of food safety and the need for a greater link of this assessment with the public interest of consumers. In short, the adaptations of the treaty (1997) meant the commitment of the EU member states in a joint policy of food safety.

In April 1997, the Commission dissolved the old scientific committees and nine new scientific committees were created, including the Scientific Committee on Food (SCF) (EC, 1997c) and the Scientific Steering Committee (SSC) (EC, 1997b). Those committees were put under the auspices of DG XXIV (nowadays called DG SANCO). The reform meant a great qualitative change in the focus on food safety problems by the EC. By way of example, although the SCF uses a majority system in the decision-making process, minority opinions are also taken in detail, which means a guarantee of transparency. The opinions (and also the minutes of the sessions) are immediately made public on the Internet (see http://europa.eu.int/comm/food/fs/sc/scf/index_en.html). In this way, all individuals, including those from business or sectorial interests, have the same access to the information, which, in turn, makes it easier to manage problems in a structured way.

The formal creation, in 2002, of the European Food Safety Authority (EFSA) (EC, 2002b) as an independent entity, with its provisional headquarters in Brussels, represents the logical solution of continuity for the present scientific committees and fulfils the overall characteristics of an era (1996–2002), which is decisive for food safety in Europe.

The key functions of this Authority are the expert analysis and scientific evaluation of risks, to provide information and communicate these to all sectors interested and to the public in general. The task of 'risk management', that is, the process by which different alternatives (detected by expert analysis) are pondered over and decisions adopted to correct problems (new legislation, controls, studies, sanctions, etc), remains in the hands of the state members and of the European Commission (EC, 2002b). EFSA is initially organised in different scientific panels (see Table 1) according to the subject of expertise and substituting the present Scientific Committees.

Table 1 - Distribution of the scientific evaluation tasks between the different panels provided for in the European Food Safety Authority, EFSA (EC, 2002b).

Full table

Safety evaluation of functional foods: legislation and scientific basis

Functional foods are a recent phenomenon in Europe, and are as yet not covered by any specific legislation except for general food legislation. The two key aspects in a potential food evaluation are safety and efficacy.

Safety is guaranteed by the application of various regulations that are in charge of controlling any novelty in food components and the obtaining processes.

As far as efficacy is concerned, both the guidelines as to the scientific evidence required in order to validate the efficacy of new components and associated foods, and the question of the so-called claims, allegations or health claims that may accompany the eventual processes of commercialisation are yet to be defined.

Depending on the type of food novelty that is trying to be introduced, and whether or not it can be considered to be functional, the evaluation of its safety will correspond to one type of specific legislation or another. In many cases, it will correspond to the area covered by the legislation of the so-called Novel Foods (EC, 1997d), the regulations on nutritional supplements (EC, 2002a), those referring to foods for particular nutritional uses (PARNUTS) (EEC, 1989) or to food additives (EC, 1995).

In addition to this, other European legislation and directives are covering aspects on food safety (see http://europa.eu.int/comm/food/fs/sfp/sfp_index_en.html).

Scientific basis for identifying functional foods

The first step in the research and development of a functional food is to identify a functional factor, condition or compound that produces a specific effect, which is potentially beneficial for health. Hence, it is necessary to investigate the interaction of this compound with other dietary elements and find out its function within the organism at different levels (genomic, molecular, cellular, physiological). One important aspect for functional ingredients is to evaluate the security margins of effective doses in order to produce the functional effects. These margins must be safe and applicable to all main population groups, including those who can be expected to consume them most. To cover this knowledge in depth requires basic fundamental research and the elucidation of the mechanism of action. Therefore, sound scientific evidence is required before a functional effect can be defined. Then, it must be proved in relevant animal models and in humans by means of well-designed epidemiological and intervention studies (Bellisle et al, 1998; Bellisle, 2002; Hasler, 2002). Identification and validation of good, quantifiable biomarkers, sensitive to dietary modulation and reflecting the step in the process between food intake and functional effects are of great help (Bellisle et al, 1998; Diplock et al, 1999; Hasler et al, 2000). As an example, a list of putative markers for key functions related to the cardiovascular system is described in Table 2.

Table 2 - Examples of potential markers for key target functions related to the cardiovascular system and candidate food components for modulation of these functions.

Full table

Phytosterol-enriched foods, which decrease cholesterol blood levels in hypercholesterolemic individuals (Hallikainen et al, 2000; Weststrate, 2000; Amundsen et al, 2002; Ntanios & Duchateau, 2002) constitute one of the first examples in Europe of a functional food whose safety has been assessed following the legislation applied to NFs (SCF, 2000,2002a). From the evaluation by the SCF, some considerations can be deduced concerning the potential benefits of the functional component, however, the evaluation is mainly concentrated on safety issues. As recently reviewed for a phytosterol-enriched food, it may sometimes be necessary to include postmarketing follow-up studies (Post Launch Monitoring) in the evaluation procedure as a palliative measure against those uncertainties that only a historical analysis can solve (SCF, 2002b).

Specific regulation on NFs

Any NF or food ingredient that has not been significantly consumed in the EU before 15 May 1997 must be evaluated with respect to its safety according to the European legislation on NFs (EC Regulation No. 258/97) (EC, 1997d), covering a very wide range of foods and ingredients. It includes transgenic foods; foods and ingredients which have a new molecular structure; those consisting of or isolated from microorganisms, fungi and algae; those from animals and plants reproduced using nontraditional methods; and those foods and food ingredients obtained with a new production process that gives rise to significant changes in the composition or structure of the foods or ingredients, which affect their nutritional value, metabolism or levels of undesirable substances.

In short, this legislation establishes that an NF must fulfil three criteria in order to be accepted as such: (a) it must not be dangerous to the consumer, (b) it must not be deceive the consumer and (c) it must not differ from the traditional food it displaces so long as this is nonadvantageous for the consumer.

To help in the implementation, an EC Recommendation has been published concerning the scientific aspects and the presentation of information necessary to support applications for the placing on the European market of NFs and NF ingredients and the preparation of initial assessment reports under the Regulation of the NFs (EC, 1997a).

All in all, to have complete, extremely rigorous information is necessary for the evaluation of NFs or NF ingredients. This information should be structured in about 11 sections (see Table 3) depending on the specific characteristics of the type of food (EC, 1997a).

Table 3 - Summary of the essential information required in the evaluation of non-genetically modified Novel Foods.

Full table

Marketing of NFs or NF ingredients can follow a more simplified procedure when they have already been considered to be substantially equivalent to existing foods or ingredients.

Substantial equivalence

A very useful tool in the assessment of NFs is based on the concept of 'substantial equivalence', which was first introduced by the Organisation for Economic cooperation and Development (OECD, 1993) and was later extended by FAO/WHO (WHO/FAO, 2000) with particular reference to foods produced by modern biotechnology. This concept embodies the idea that existing organisms used as food or as food sources can serve as a basis for comparison when assessing the safety of an NF. Substantially equivalent NFs are considered comparable, with respect to safety, to their conventional counterpart. Establishment of substantial equivalence is not a safety or nutritional assessment in itself, but an approach to compare a potential NF with its appropriate traditional counterpart. It constitutes a starting point to orientate further research into more concrete safety aspects. Conversely, if an NF does not show substantial equivalence to an existing one, this does not imply that it is unsafe: It merely indicates the need to evaluate it on the basis of its particular composition and/or properties. The concept of substantial equivalence can also be extended to the assessment of novel sources and new processes (EC, 2002a).

Food supplements, fortified foods and upper levels of nutrients

Functional foods are generally produced by using different approaches: by eliminating a component known as causing a deleterious effect to the consumer, by adding a component that is not normally present or by increasing the concentration of a component naturally present in foods to produce beneficial effects, and by replacing a component (potentially deleterious) with another for which beneficial effects have been demonstrated. Taking into account that functional foods are usually made by adding or removing some functional substances, the present control strategy for food supplements and enriched or fortified foods has a significant implication for functional foods (Roberfroid, 2000; Kwak & Jukes, 2001).

A proposal on fortified foods laying down provisions for marketing foods to which nutrients such as vitamins and minerals have been added has been announced in the White Paper on Food Safety (CEE, 2000). The Directive 2002/46/EC relating to food supplements establishes harmonised rules for the labelling of food supplements and introduces specific rules on vitamins and minerals in food supplements (EC, 2002a).

An important work in relation to supplements is the one concerning the establishment of maximum tolerable levels (ULs) for the daily intake of vitamins and minerals, currently under development in the EU. Minimum intake needs of these nutrients have been established as limits in order to avoid the appearance of alterations or illnesses due to their deficiency. In contrast, ULs of nutrients have to be defined in order to be able to adequately control the maximum quantities that can be eaten, for instance in relation to supplemented foods. From the point of view of nutritional security, legislation does not require minimal nutritional values for common foods; this is only required for nutritional allegations. Nevertheless, the European Council has raised some important questions to be dealt with, such as the risk involved in modifying feeding habits due to the negative perception of those foods which do not carry associated allegations of health.

The definition of clear guidelines to establish scientific evidence should be laid down, and would probably include human studies with appropriate animal models and should also identify markers, as commented above (Bellisle et al, 1998; Palou et al, 2003). Studies tailored on a case by case basis will also be needed.

Functional food claims

Discussing food claims means addressing the complex issue of communication of health benefits of foodstuffs between consumers and producers. Consumers are increasingly health-conscious and want to obtain more information about the food they buy. At the same time, the industry wants to take advantage of the developments in food science and is investing heavily in innovative projects. However only a food which successfully conveys its health benefits in a meaningful way to the consumer is an incentive for the industry.

The fundamental principle defining food allegations or claims is that they must be scientifically proved, not ambiguous and clear to the consumer. However, the term 'health claim' itself has different definitions depending on the country. Probably the most accepted is that defined by the Codex Alimentarius: 'any representation which states, suggests or implies that a food has particular characteristics relating to its origin, nutritional properties, nature, production, processing, composition, or any other quality'. The American definition is quite lax: it is any claim, that either expressly or implicitly characterises the relationship between a substance and an illness or a healthy condition. Japan introduced the concept of Foods for Specified Health Use (FOSHU). The Council Directive 90/496/EEC on nutrition labelling includes a definition of 'nutrition claim' as any representation and any advertising message that states, suggests or implies that a foodstuff has particular nutritional properties due to the energy and/or nutrient content (EEC, 1990).

In Europe, in the absence of a specific Directive on claims for foodstuffs, EU members can apply different interpretations of the existing labelling legislation (EC, 2000). The EC is specifically working on a directive that specifies the conditions under which functional and nutritional claims may be made (SANCO, 2001).

There are many types of nutrition claims currently accepted: a nutrient content claim describes the level of a nutrient contained in a food, for example, low on sodium, source of calcium, etc; the comparative claims compare nutrient levels and/or energy values of two or more foods; other claims state the functionality of the nutrient, such as regular exercise and a healthy diet with enough calcium helps to maintain good bone health.

The Consensus document on Scientific Concepts for Functional Foods in Europe (Diplock et al, 1999) identifies two types of health claims that should be allowed and are currently under discussion to cover specifically the additional particularities of functional foods (SANCO, 2001): (a) enhanced function claims: concerning specific beneficial effects of nutrients and non-nutrients on biological, physiological or psychological activities, beyond those established by their traditional nutritional role; (b) reduction of disease risk claims: which associate the food intake of a functional ingredient to the reduction of a disease risk, such as: diets low in saturated fat and cholesterol may reduce the risk of coronary heart disease. Recently, a third category concerning nutrient-function claims has been added.

It is evident that the development of functional foods must be accompanied by the application of suitable controls and follow-up to guarantee that the claims are used to obtain their best effect in promoting public health and protecting the consumer against misleading information.

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